抄録
The super-effective-field theory (SEFT) proposed by one of the present authors (M.S.) is applied to the antiferromagnetic planar model on a two-dimensional triangular lattice (AFPT model) in order to understand the nature of chiral order by a series of mean-field-type approximations. Approximants are constructed for clusters of various sizes up to 651 sites and calculated by use of the Monte Carlo technique. The critical temperature Tc and the exponent γ are estimated as Tc=0.5096(5) and γ=1.7(2) respectively. Some of characteristic features of this model such as the relation between the KT-like and Ising-like transitions are discussed from a viewpoint of the present theory.
